In general a blockchain is defined as a distributed system which records and stores transaction records. Blockchain more specifically is defined as “…a shared, immutable record of peer-to-peer transactions built from linked transaction blocks and stored in a digital ledger.”

Blockchain is also similar to a database which stores information, however the main difference is that the data is located in a network of personal computers called nodes where there is no central entity such as a government or bank controlling the data.

Instead, all data is shared publicly although the contents of each data is only accessible to those with permission. Below is a diagram to illustrate how information is stored in distributed network compared to a centralised and decentralised network.

Figure 1: Illustration of network comparisons between blockchain, centralised and decentralised networks. (Petre, 2016b)

Furthermore, underlying the blockchain principle are cryptographic techniques. This allows each participant in the network to interact without pre-existing trust between parties, in regards to storing, exchanging and viewing information.

Interactions with the blockchain become known to all participants and require verification by the network before information is added, enabling trustless collaboration between network participants while recording an immutable audit trail of all interactions.

Each participant connected to the blockchain network has a secret private key and a public key that acts as an openly visible identifier. The pair is cryptographically linked such that identification is possible in only one direction using the private key. As such, one must have the private key in order to unlock a participant’s identity to uncover what information on the blockchain is relevant to their profile.

Figure 2: Example of a Healthcare Blockchain ecosystem that can be implemented (Deloitte, 2016).

How can blockchain be used in healthcare?

  • Drug Traceability where each transaction between drug manufacturers, wholesalers, pharmacists and patients can be tracked to verify and secure drug product information important for tackling issues such as counterfeit drugs.
  • Improvement and authentication of health records and protocols on record sharing.
  • Smart contracts where certain rule-based methods are created for patient data access. Here, permissions can be granted to selected health organisations.
  • Clinical trials where altering or modifying data from clinical trials fraudulently can be eradicated.
  • Precision medicine where patients, researchers and providers can collaborate to develop individualised care.
  • Genomics research via access to genetic data secured on blockchain
  • Electronic health records (EHRs) 
  • Nationwide interoperability 

Figure 3: Illustration of how a blockchain for drug traceability could be used (Petre, 2016a 2017).

Blockchain specific application to EHRs:

Blockchain can help enhance three major features of EHR systems which are:

  • Immutability via File Integrity where each event on the blockchain has a unique hash corresponding to the contents of a record. This means users can verify if the contents of the record have been changed or not.
  • Cybersecurity via Data Access Management where each hash may contain particular user permissions for doctors, patients, nurses or any authorised user or device. Therefore, only authorised personnel may access record information.
  • Interoperability via Collaborative Version Control where each party has a record linked to the original record that is registered to the blockchain. This way, everyone who has the appropriate role and responsibility, can append information to the record avoiding issues such as inconsistent or duplicate records.

Current Market and industry trends in Blockchain

According to Statista (2016), the size of the blockchain technology market worldwide from 2017 to 2021 will be expected to grow to 2.3 billion U.S. dollars by 2021 from 339.5 million U.S. dollars in 2017. These estimated forecasts are based on an annual constant growth rate of 61.5%.

Factors driving the blockchain market include:

  • Limited access to population health data.
  • Inconsistent rules and permissions for accessing patient data.
  • Varying data standards which reduces interoperability as a consequence of non-compatibility between systems.
  • Privacy and security such as confidentiality of protected health information and from hacking attacks.
  • Fraud and abuse.
  • Consumer engagement such in in the form of disease and management and clinical outcomes.

Factors inhibiting the growth of the blockchain market include:

  • Immature infrastructure where most blockchain technology is untested and experimental.
  • High development costs.
  • Patient-controlled data can be risky.
  • Scalability constraints in terms of tradeoff between volume of transaction and computer power for processing time of transactions.


Blockchain technology applications in healthcare shows promise for solving issues such as its used in EHR distribution of data and nationwide interoperability. However, more research, trials and experiments must be carried out to ensure a secure and established system is implanted before using blockchain technology on a large scale in healthcare.

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